Lubricator for tailstock centers



Dec. 11 1923.

.7 F. MULLER LUBRICATOR FOR TAILSTOCK CENTERS Filed April 27. 1921 HQG.484

J 5m mvamtoz a?) KM 7 an /"a Patented Dec. 11, 1923.

unurso STATES PATENT OFFICE.

FRIEDERICH MIILLER, OF HARTFORD, CONNECTICUT, ASSIGNOR TO PRATT & WHIT-NEY COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

LUBRICATOR FOR TAILSTOCK CENTERS.

Application filed April 27, 1921. Serial No. 464,911.

To aZZ whom it may concern:

Be it known that I, FRIEDERICH Mi'JLLEn, a citizen of the United States,residing at Hartford, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements inLubricators for Tailstock Centers, of which the following is aspecification.

This invention relates to spindle lubricating means and particularly tosuch a means as applied to a tails-took spindle for lubri eating thework supporting center thereof at its point of contact with the work.

The primary object of the invention is to provide a lubricating pumphaving improved means for operating the same in synchronism With thelongitudinal movement of the spindle and center whereby a lubricant isautomatically sup-plied to the center at its work engaging surface uponthe engagement of the center with the work.

More specifically, it is an object of the invention to provide alubricating pump in combination with a tailstock, and an operativeconnection between the pump and spindle whereby, upon the feeding of thespindle toward the work, the pump is automatically operated to supply aquantity of lubricant to the center at its point of enga ement with thework.

ith the above and other objects in view, my invention consists infeatures of construction and operation set forth in the followingspecification and illustrated in the accompanying drawing. In suchdrawing annexed hereto and fonninga part of this specification, I haveshown my invention as embodiedin alathe tailstock of the typeillustrated in my Patent No. 1,318,223, dated October 7, 1919, but itwill be understood that the invention can be otherwise embodied and thatthe drawing is not to be construed as defining or limiting the scope ofthe invention, the claims appended to this specification being reliedupon for that purpose.

Referring tothe figures of the drawing:

Fig. 1 is a ertical longitudinal sectional view of a tailstock having myinvention embodied therein.

Fig. 2 is a cross section thereof on the line 2.2 of Fig. 1, the spindlehowever not being illustrated.

Fig. 3 is a bottom plan view of the mechanism illustrated in Fig. 2.

Fig. 4 is a detail view taken on line 4-4 of Fig. 2.

Fig. 5 is a fragmentary elevation of the spindle Fig. 6 is a fragmentarysectional view of the spindle taken on line 6-6 of Fig. 5.

In machines comprising a spindle having a center for rotatablysup-porting a piece of work, it is very desirable that the center besupplied with a lubricant at its point'ofcontact with the work. Thepresent inven tion provides means for so lubricating the center and isadapted to operate automatically to supply such lubricant uponengagement of the center against the work. As illustrated in thedrawing, I provide a lubricating pump and preferably mount the same onthe longitudinally movable spindle. Means is provided in connection withthe spindle and the pump piston for operating the latter on a suctionstroke during the rearward movement of the spindle and on an oildischarging stroke during the forward movement of the spindle. Themechanism is preferably so constructed as to provide for preventing theflow of oil to the center except when the same is in engagement with thework. The special details of the construction illustrated in the drawingwill now be described.

Referring to the drawing, 1 represents the main frame or body of atailstock, this being adjustably mounted in the usual way on theguideways 2, 2 of a lathe .bed 3. The body part of the tailstock can beclamped to the bed by any usual or preferred means such as indicated asa whole by 4. Extending longitudinally through the body of the tailstockis a cyllndrical aperture in which is slidably mounted a sleeve 5.Preferably,

for reasons which will presently appear, the

aperture is formed in a support or spindle 6 which itself islongitudinally movable in an aperture in the main ,frame of thetailstock.

The aperture of the sleeve 5 is tapered at one end to receive a center 7in the usual manner. At the other end the aperture of the sleeve 5 isenlarged to receive a coil spring 8 which serves to move the sleevetoward the left. At its inner or left-hand end the spring 8 abutsagainst a washer 9 positioned'within the sleeve, and at its outer orright-hand end the spring abuts against a member! or bushing 11 which isadjustable within the sleeve, preferably being screw threaded.Preferably a bushing 10 is interposed between the spring and the bushing11. Forv limiting the movement of the sleeve 5 toward the left there isprovided a stop in the form of a cap 12 surrounding the sleeve andengaging a beveled surface thereof, this cap having threaded engagementwith the spindle 6.

With the parts in the positions shown, the sleeve 5 is held in itsleft-hand position in engagement with the cap 12, but it is free toyield toward the right against the action of the spring 8 when pressureis applied to the center 7. The spring pressure can be adjusted byturning the bushing 11. The adjustment shown, with the sleeve 5 held bythe spring, is that which is ordinarily desirable for turning lightslender work. For

.heavier work, when no yielding of the tailstock center is desired, thebushing 11 is turned and moved into firm engagement with the right-handend of the sleeve 5, thus forcing the sleeve into firm engagement withthe cap 12. This looks the sleeve and holds it rigidly against anymovement with respect to the spindle 6. A

Preferably, for preventing the sleeve 5 from turning in the spindle 6,there is provided a screw 13 in the spindle 6 which projects into akeyway in the sleeve 5.

It will be observed that there is an opening entirely through the outerpart of the sleeve 5 thus making it possible to insert a rod for drivingout the center 7 when neces sary.

When the tailstock is to be used as a part of an automatic lathe, meansis provided for automatically moving the spindle 6 to bring the center 7into and out of engagement with the work. As illustrated, a collar 14 isslidably mounted on the spindle 6, havinv adjustable frictionalengagement therewith by means of a suitable friction shoe, as

shown in my Patent No. 1,318,223, dated Oct. 7, 1919. The collar 14 isconnected with a longitudinal rod 16 which is adapted to be moved by thelathe mechanism at-the proper times. When the rod 16 is moved toward theleft it carries the collar 14 with it and the collar 14 moves thespindle 6 with the center until the center engages the work, Thereafterthe collar 14 slides on the spindle. The frictional resistance at 15should be less than the resistance offered by the spring 8, so that thespindle 6 will not be moved relatively to the sleeve 5.

A lever 17 is pivotally mounted on the main frame of the tailstock andat its righthand end carries a roller 18 adapted to engage a cam surface19 formed on the collar 14. The lever 17, at its right-hand end, isadapted to engage a shoe 20 which is in contact with the spindle 6. Thecontinued movement of the collar 14 toward the left forces the camsurface 19 under the roller 18, thus swinging the lever 17 in thecounterclockwise direction and pressing the shoe 20 into firm engagementwith the spindle 6. In this way the spindle is firmly held against anyreturn movement and the center 7 is firmly held in engagement with thework and is permitted to move, if at all, only against the resistance ofthe spring 8. When the rod 16 moves the collar 14 in the other directiontoward the right, the lever 17 is released, thus releasing the pressureon the spindle 6. Further movement of the collar 14 causes the spindle 6to be moved toward the right, thus withdrawing the center fromengagement with the work.

The mechanism thus far described comprises substantially the subjectmatter of my aforesaid Patent No. 1,318.223. The mechanism illustratingan embodiment of the present invention will now be described.

A pump represented at 21 is adapted to supply a lubricant to the center7 of the tailstock at its work engaging surface. I preferably mount thispump on the spindle 6 and provide means adapted to operate the pump uponthe reciprocation of the spindle. As illustrated, the pump cylinder isformed in a yoke or collar 22 secured to the spindle by means of aclamping screw 23. 24 represents an oil cup or reservoir screw threadedinto the cylinder at 25. A valve 26 normally held closed by means of aspring 27 and surrounding the valve stem is provided at the lower endsof ports 28. The oil cup may be filled by removing a closure plug 29therein.

, The piston 30 within the cylinder is normally held in its inwardposition by means of a spring 31'surrounding the piston rod 32 betweenthe piston and a closure plug 33 screw threaded into the cylinder.

yoke is forked at its free end to engage against check nuts 37 on thepiston rod. 38 represents a wedge member screw threaded into the bodymember 1 and freely slidable in a bore 39 in the yoke in a position toengage a projecting portion 40 on the arm 34 as the spindle isreciprocated.

A port 41 leads from the pump cylinder through the yoke to an elongatedrecess 42 on the inner surface of the yoke. 43 and 44 represent portsextending from the recess 42 through the spindle 6. 45, 46, and 47represent ports extending through the sleeve 5 and center 7 to the workengaging end of the latter. 1 46 are preferably provided around thesleeve 5 and center 7 in connection with the ports 45 and 46 therein.Ports 43 and 44 are screw threaded and either of such ports is adaptedto be closed by means of a plug 48. With the bushing 11 set in theposition shown in F ig.. 1 wherein the sleeve 5 has Circumferentialrecesses 45 and' the pump piston for drawin a sliding movement withinthe spindle 6, the port 43 should be closed by the plug 48 and the port44 left open. When the bushing 11 is set into engagement with the sleeve5 so that the latter has no sliding movement within the spindle 6, theport 44 should be closed by the plug 48 and the port 43 left open. Thepurpose of such construction is hereinafter described.

With the mechanism adjusted as shown in Fig. 1, the operation is asfollows: As the spindle 6 is withdrawn from the work, the projectingportion 40 on the arm 34 engages the wedge 38 and draws the piston 30outwardly thus drawing a quantity of oil through the valve 26 into thecylinder. As the spindle is moved forwardly toward the work the spring31 forces the piston inwardly and compresses the oil in the cylinder andports 41 to 45. However, since the port-43 is closed by the plug 48'nooil can enter the center ports until port 44 comes into communicationwith port 45. Spring 8 normally keeps the sleeve 5 in the forwardposition illustrated in Fig. 1. However, when the center engages againstthe work further movement of the spindle 6 will slide the same oversleeve 6 and thereby bring ports 44 and 45 into register, whereupon oilwill pass into the several ports to the work engaging end of the center7. l/Vhen the bushing 11 is adjusted to engage directly against thesleeve 5 so that the sleeve has no longitudinal movement in the spindle6, the pump cylinder is at all times in communication with the centerport 47 through the port 43, port 44 being closed by the plug 48.

What I claim is:

1. In a machine tool, the combination of a spindle, means for moving thespindle longitudinally, a lubricating pump, an oil conduit leading fromthe pump to the spindle, and means controlled by the longitudinalmovement of the spindle and operative on the pump for discharging aquantity of oil from the pump to the spindle.

2. In a machine tool, the combination of a spindle, means for moving thespindle longitudinally, a lubricating pump, an oil conduit leading fromthe pump to the spindle, and means controlled by the longitudinalmovement of the spindle and operative on the pump piston for drawing acharge of oil into the pump as the spindle recedes and for discharginga. quantity of oil from the pump to the spindle as the spindle advances.

3. In a machine tool, the combination of a spindle, means for moving thespindle longitudinally, a lubricating pump, an oil conduit leading fromthe pump to the spindle and mean controlled by the longitudinal movementof the spindle and operative on a charge of oil into the pump as thespin le recedes and for discharging a quantity of oil from the pump tothe spindle as the spindle advances, the movement of the spindle in onedirection acting positively on the piston to move the same.

4. In amachine tool the combination of a spindle, means for moving thespindle longitu-dinally, a lubricating pump, an oil conduit leading fromthe pump to the spindle, means operating positively on the pump pistonby the longitudinal movement of the spindle for drawing a charge of oilinto the pump as the spindle recedes, and a spring operative on thepiston to move the same in the opposite direction to discharge aquantity of oil from the pump to the spindle as the spindle advances.

5. In a tailstock, the combination of a body member, a center supportingspindle slidably mounted therein, a lubricating pump mounted on thespindle, an oil conduit leading from the pump through the spindle to thetailstock center, and means controlled by the reciprocating movement ofthe spindle for operating the pump to force oil through the conduit tothe center.

6. In a tailstock, the combination of a body member, a center supportingspindle slidably mounted therein, a yoke mounted on the spindle, alubricating pump mounted on the yoke, an oil con-duit leading from thepump through the yoke and spindle to the tailstock center, and meanscomprising a cam on the body member for operating the pump to force 011through the conduit to the center upon reciprocating movement of thespindle.

7. In a tailstock, the combination of a body member, a spindle slidablymounted therein, a work supporting center mounted in the spindle, meansfor moving the spindle longitudinally, a lubricating pump, and means forautomatically supplying a quantity of lubricant from the pump to thecenter at its point of contact with the work only after the center hasengaged the' work.

8. In a tailstock, the combination of a bodyv member, a spindle slidablymounted therein, a center supporting sleeve slidably mounted in thespindle, the spindle and sleeve each having a duct therein, and a sourceof lubricant supply in communication with the duct in the spindle, therelative arrangement of the two ducts being such that as the sleeveslides rearwardly in the spindle the two ducts come into. registerwhereby a charge of oil is discharged into the sleeve.

9. In a tailstock, the combination-of-a the spindle, the relativearrangement of the two ducts being such that as the sleeve slides in thespindle against the action of the spring, the two ducts come intoregister whereby a charge of oil is discharged into the sleeve.

10. In a tailstock, the combination of a body member, a spindle slidablymounted therein, a center supporting sleeve slidably mounted in thespindle, a spring normally holding the sleeve in a forward position inthe spindle, the spindle and sleeve each having a duct therein, a pumpin communication with the duct in the spindle, the relative arrangementof the two ducts being 15 means operated by the sliding movement of 20the spindle for operating the pump.

In testimony whereof, I hereto affix my signature.

FRIEDERICH MULLER.

